The present invention relates in general to processing methods and apparatus for removing flesh from the bones of fowl or animals. More particularly, the invention is ideally suited for use in removing the flesh from the type of bone having a knuckle or enlargement at each end of the bone.
The automated removal of raw flesh or meat from a knuckled bone poses special problems. For instance, raw meat has a tendency to adhere to the bone and the removal thereof necessitates a tearing or shearing of the meat from the bone. However, once removed, the meat alone can be cooked or processed without having to waste energy in cooking or further processing the bone. Also, the separated bone can be subjected to additional processing to make bone meal or other byproducts. While it is possible to remove one knuckle from the bone and then pull the bone through the meat, such a solution is particularly objectionable because of the possibility of bone splinters or chips contaminating the meat.
Fully disclosed in U.S. Pat. No. 4,299,009 is one type of boning machine which grips the foot end of an animal bone with a fixed set of holding jaws. Another set of movable jaws closes around the bone at a position near the holding jaws, and is moved away from the holding jaws thereby stripping the flesh from the bone.
Other approaches taken in the prior art involve the use of multiple blades for stripping the meat from the knuckled end of a double-knuckled bone. U.S. Pat. Nos. 3,261,054, 3,402,423 and 3,457,586, for example, utilize stripping blades which are biased against the surface of the bone to effect the removal of the meat from the bone. These techniques are also undesirable because of the high possibility of bone chippings for scrapings being mixed with the meat. U.S. Pat. No. 1,435,877 is a boning device with sharp blades which are rotatable around the bone to remove the meat therefrom. In this latter device the tips of the knife-like blades form an opening to accommodate the bone which opening must be manually adjusted by the operator according to his best guess as to where the knuckle enlargement is located within the meat. Such a device is not practical in today's automated high speed meat processing plants.
Although it is realized that the mentioned boning machines perform a function similar to that of the present invention to be described, it is believed that the invention provides additional advantages. It is therefore a principal object of the present invention to provide a boning machine which pulls a knuckled bone through an apertured opening, and as the knuckle approaches proximate the opening, the opening is caused to enlarge enough just to allow the knuckle to pass therethrough.
It is another object of the present invention to provide a boning machine with blade edges which encircle the bone but which are not biased against the bone.
It is a corollary object of the present invention to provide a boning machine with stripping blades which encircle the bone but which do not rotate around the bone. The meat is separated from the bone by the action of the bone being pulled through the apertured opening.
It is a further object of the invention to simplify both the machine structure and the boning operation by connecting the meat stripping blades, as well as the bone holding blades, directly to the shafts of double-acting cylinders, where such shafts are of the type being nonrotatable within the respective cylinders.
It is another object of the present invention to provide a boning machine with a pair of blades mounted for movement so as to form an aperture opening of a predetermined first size to accommodate the general diameter of the elongate portion of the bone, and a second predetermined size to accommodate the knuckle portion of the bone.